# Dictionary:Gauss’s theorem

The total flux through any closed surface is equal to times the source strength *m* enclosed by the surface

Here, **ds** is a vector surface element and *dv* a volume element. (The is often deleted in the *mks* system.) *k* is a constant that depends on the units of measure. This can also be expressed in terms of the flux density or field strength **g**, the source density , and the potential *U*. may be electrical flux if *m* is electrical charge. In the *mks* system, is in webers if *m* is in coulombs and , or may be gravitational flux if *m* is mass, in which case , where is the gravitational constant. Or may be magnetic flux if *m* is magnetic pole strength.

Also called **Gauss's law**: The equality between the surface and volume integrals involving **g** is also called the *divergence theorem* (q.v.). This theorem postulates the inherent nonuniqueness of potential fields.